The present invention relates to manufacturing management, and particularly to a dispatch method and system for Long-duration Processing Batch Equipment (LPBE) that reserves lots at preceding steps in the manufacturing process.
In semiconductor manufacturing, LPBE, such as furnace equipment utilizes long process time and batch process. As it requires several hours to rework defective lots, processing quality and manufacture scheduling are important.
The manufacturing department controls process quality by defining processing time constraints for each lot passing through LPBE. The time between tracking out from the preceding step's equipment and tracking in to the subsequent step's equipment for each lot should conform to the processing time constraint. Before entering LPBE, lots must enter the preceding step's equipment for removal of residual particles in advance. In practice, each preceding step's equipment provides lots for different LPBE. Since there is no mechanism between the preceding step's equipment and LPBE to manage lot dispatch and stream, the quantity of dispatched lots for each LPBE may differ. Therefore, the utilization rate of LPBE having fewer lots may be decreased, and those having more lots may be delayed, undermining the processing time constraint, such that the lots needs to be reworked, thereby wasting processing resources.